How do you keep yours from cracking?
Marty,
I will send you some NEW windows, They should fit, you will need to put the slightest amount of silicone to the recessed area and put the new window in, I know it will work as I have done it on mine.
The new windows/heads have NO screws, I asked PMF to make it a press fit and they hit a home run, but they will work on the head you have too, and you can get rid of the 4 screws